Could You be Suffering from Low Energy Availability?

March 19, 2024

As female athletes, it’s important to prioritize fueling strategies for performance and recovery. As runners, we want to run well, have optimal energy and recovery so we can do it all over again the next day!

I often hear from women in their mid – late 30s who are concerned about body composition changes. They don’t understand why their body is changing despite the effort of training and nutrition. And, often think they need to train harder and eat less, because their body doesn’t respond in the same way it used to.  But, this can actually backfire on you!

Energy expenditure is the amount of calories or energy your body needs to exist in the day. Let me break this down for you.

We naturally have an increase in the amount of calories or energy your body needs right when we wake up. Then, you might go for a run and you’re expending calories, plus we need more calories to refuel post run as the body is trying to recover and repair. Later in the day, you might do strength training, yoga, Pilates or go for a hike. Again, this increases the amount of energy you need in a day as well as the energy for recovery. Plus, we have to take into account daily movement (other than exercise) until you go to bed. All of this adds up to the amount of calories or energy your body needs.

This is on top of what’s called your resting metabolic rate, which is how many calories your body needs just to exist, without additional movement.

Energy availability is the baseline amount of energy you need after you remove the amount of calories that you’ve expended during exercise as well as the amount that you take in.

The food you consume gives you X amount of calories. Then we look at energy expenditure from exercise and movement and this gives you the amount of energy your body has left over to do all the functions it needs to exist, like your heart beating, brain, endocrine system and immune system working.

As women get into their mid-late 30s, we have hormonal fluctuations which lead to body composition changes. And, we often wonder what is going on? We’re still training hard and eating the same, but not seeing any change in physique or increases in performance, plus we’re putting on body fat.

Unfortunately, the default is often, I must train harder and I need to eat less.

We fall into this idea of calories in calories out, which often puts us into a state of low energy availability or LEA.

Healthy caloric intake for women is around 40 to 45 calories per kilogram of fat-free mass per day. For example:  if you have 100 lbs of fat free mass = approximately 1800 – 2025 calories per day.

This allows us to train, recover, adapt to the training, have a healthy immune function, maintain bone mineral density and lean body mass.

When dropping below 30 calories per kilogram of fat-free mass, approximately 1350 calories per day, issues begin to arise with the body trying to support itself for general function. This causes a suppression of hormone function, especially thyroid function, a disruption in estrogen and progesterone, a disruption in appetite hormones and a suppression in bone formation.

It’s important to understand, it’s not as simple as calories in calories out. The goal is to support our daily activities including training and life stress, as well as the amount of calories we need to support our entire system, so we don’t perpetuate hormone dysfunction and the loss of bone mineral density. We want to prevent elevated cortisol, the stress hormone, and signaling the body that there’s not enough nutrition to adapt to change.

Signs and Symptoms of Low Energy Availability


➡Decrease in performance

➡Longer recovery times

➡Increase in injuries, particularly stress fractures

➡Loss of muscle

➡Absence of or abnormal periods

➡Decreased concentration, coordination and focus

To prevent low energy availability and fuel your body for optimal performance and recovery, focus on fueling before and after each workout. Even a small snack like a banana with nut butter, energy balls, toast or bagel with nut butter before workout, followed by a regular breakfast afterwards and balanced meals + snacks throughout the day.

If you’re experiencing symptoms of low energy availability, getting in touch with a nutritionist specializing in sports nutrition is key. We can help you understand your symptoms and how your fueling habits may be hindering your training, performance and overall health. Then, help you make a fueling plan for optimal performance and recovery.